A thought; if you have a true cargofire (not a false warning, but with real noticeable smoke), the airplane is a write off from that very moment. Even if you land it within minutes, it will almost certainly burn out.
So there's no need to save the plane, just it's occupants.
If there's not an airport in the immediate vicinity, put it on any flat piece of land or ditch it.
17 minutes is the average survivable time with a cargo or cabin fire. Anything over that and you're on borrowed time.
I tend to agree if you're dealing with an uncontrollable (battery related?) fire, but how do you know whether you're dealing with a 'normal' fire or an uncontrollable battery fire when a fire warning sounds?
Investigating the cause of the fire (uncontrollable battery fire or not), decision making, finding suitable terrain/water and subsequent ditching from a normal 744 cruising level
within 17 minutes would be totally unrealistic IMHO.